[Correlation of epidermal growth factor receptor mutations and HER2/3 protein expression with clinical outcome in advanced non-small cell lung cancer patients treated with gefitinib].

BACKGROUND AND OBJECTIVE: The effect of gefitinib on advanced non-small cell lung cancer (NSCLC) was various. How to choose the sensitive patients and improve the effect was difficulty in clinic. This study was to assess the correlation of epidermal growth factor receptor (EGFR) mutations and HER2/3 protein expression with the effect of gefitinib on Chinese patients with advanced NSCLC. METHODS: From May 2002 to February 2005, a total of 106 Chinese NSCLC patients who had failed at least one chemotherapy regimen were treated with gefitinib 250 mg once a day. The mutations in the exons 18-24 of EGFR gene were detected in the tumor tissues from 106 patients before the treatment of gefitinib, and HER2/3 expression in 84 tumor samples were detected by immunohistochemistry. RESULTS: Mutation was identified in 32 (30.2%) tumor tissues. Overall remission rate was significantly higher in the HER2 high expression patients than in the HER2 low expression patients (36.8% vs 17.4%, P=0.044). HER2 and HER3 expression levels were not associated with time to progression (TTP) and overall survival (OS). The patients with HER2/3 single high expression had relatively longer TTP and OS than those with HER2/3 single low expression (6.1 vs 9.1 months, P=0.725; 6.1 vs 9.0 months, P=0.862), while those with concomitant HER2/3 high expression had significant longer TTP and OS. EGFR-mutated patients with HER2 expression or high HER2 and HER3 expressions were more sensitive to gefitinib. CONCLUSION: EGFR mutations combined with HER2/3 expressions is a significant predictor for gefitinib efficacy on Chinese patients with advanced NSCLC.

EGFR mutations and HER2/3 protein expression and clinical outcome in Chinese advanced non-small cell lung cancer patients treated with gefitinib.

BACKGROUND: To assess the role of various epidermal growth factor receptor (EGFR) mutations and HER2/3 protein expression as predictive markers of responsiveness to gefitinib therapy in Chinese patients with advanced non-small cell lung cancer (NSCLC). METHODS: A total of 106 Chinese NSCLC patients who had failed at least one chemotherapy regimen received gefitinib 250 mg once daily. All the 106 tumors from these patients were screened for mutations in the EGFR exons 18-24, and 84 tumors were studied by immunohistochemistry for HER2/3 expression and correlated with clinical treatment outcome. RESULTS: Patients with EGFR mutations had a significantly higher overall response rate (ORR), longer time to progression (TTP) and overall survival (OS) compared with those with wild-type receptor. No difference in ORR was observed between patients with exon 19 deletion and patients with other EGFR mutations. ORR in HER2-positive patients was significantly higher than in the HER2-negative group, irrespective of EGFR mutational status, and a trend for better ORR was observed for HER3-positive patients. HER2 and HER3 expression levels were not associated with any difference in terms of TTP and OS. Nevertheless, when considering the subgroups of non-responders to gefitinib, median TTP in patients with mutated EGFR was significantly longer than in those with no mutations (8.0 vs. 3.0 months, P = 0.0065). EGFR-mutated patients had no significant difference in ORR, TTP and OS according to HER2 and/or HER3 expression. CONCLUSIONS: EGFR mutations are effective predictors for gefitinib efficacy in Chinese patients with advanced NSCLC. HER2 and HER3 expression does not provide any additional information for selecting patients most likely to benefit from gefitinib treatment.

[EGFR mutation predicts response and prognosis in iressa-treated advanced-stage non-small cell lung cancer].

OBJECTIVE: To investigate the correlation between mutation in EGFR tyrosine kinase domain and tumor response as well as prognosis in advanced stage non-small cell lung cancer (NSCLC) treated with iressa. METHODS: From May 2002 to Feb. 2005, iressa was orally administered at a dose of 250 mg once daily for 106 advanced stage NSCLC patients until occurrence of disease progression or intolerable toxicity. Cancer tissue was obtained from these patients, and DNA was extracted for analysis of mutation in exon 18 to 24 of EGFR. Exon 18 to 24 of EGFR were amplified by nest PCR, sequenced and analyzed from both sense and antisence directions. RESULTS: Primary NSCLC tissue specimens consisted of 25 frozen tissue blocks and 81 paraffin-embedded tumor tissue blocks from 106 consecutive NSCLC patients. Mutation was found to be more frequent in the adenocarcinoma than in the squamous cell carcinoma (35.9% vs 14.3%, P =0.033). Mutation was identified in 32 patients (30.2%). Response rate to iressa was 71.9% in the patients with EGFR mutation versus 13.5% in those without mutation (P <0.01). Compared with the patients without EGFR mutation, those with mutation had longer overall survival (median, 13.45 vs. 5.25 months; P<0.01) and median time to progression (median, 8.35 vs. 3.0 months; P <0.01). CONCLUSION: EGFR mutation may be positively correlated with the response and survival in advanced stage Chinese NSCLC patient treated with iressa.

[Expression of human mu-opioid receptor cDNA in CHO cell].

Opioid receptor, is classified into three subtypes, mu, kappa and delta, with the mu-type receptor plays important roles in opioid analgesia and opioid addiction. The cDNA encoding mu-type receptor was obtained by RT-PCR from human brain RNA and was cloned into pcDNA3.1(+). The resultant recombinant plasmid pcDNAMORs were transfected into CHO cells by liposome. After PCR identification, the positive clone were treated with agonist and antiagonist were tested for their competence of signal transduction. CHO cells that contained mu-opioid receptor in the expression vector pcDNA3.1(+) acquired naloxone-blockable high-affinity specific binding of morphine and DAMGO. The concentration of cAMP in CHO cells transfected with pcDNAMOR was reduced after binding to morphine and DAMGO, and increased after binding naloxone. These results indicate that the mu-type receptor expreesd on the CHO cell has similar biological property as the nature receptor. The availability of these specific cell lines will facilitate the drug development and promote our understanding the mechanism underlying opiate addiction.

[Co-expression of CFA/I and CS6 of Enterotoxigenic Escherichia coli ( ETEC ) in Shigella flexneri 2a T32 Derivative Strain FWL01].

Among the known colonization factors of enterotoxigenic Escherichia coli (ETEC), CFA/I and CS6 (the common antigen in the CFA/IV fimbrial antigens ) are two of the most prevalent fimbriae found in clinical isolates but are never expressed by the same wild-type strains. In this study, CFA/I and CS6 of ETEC were co-expressed in Shigella flexneri 2a T32 derivative strain FWL01 by using a host-plasmid lethal balancing system based on asd gene. The results indicate that the recombinant plasmid carrying CFA/I and CS6 could be stably integrated in FWL01. Expression of the two antigens did not interfere the host growth. The results of immunofluorescence analysis showed that CFA/I and CS6 were localized on the surface of the strain FWL01. In Balb/c mice orally immunized with the recombinant strain, the immune responses against CFA/I and CS6 were observed. Those observations show the feasibility of a multivalent vaccine expressing different fimbrial antigens in attenuated Shigella flexneri.

Cloning and Expression of alpha-Bungarotoxin Gene.

The genetic engineering methods to produce the snake neurotoxin obviously have potential advantages over the traditional methods of extracting neurotoxin from snakes. This work was to study the expression and the feasibility of scaled production of snake neurotoxin in the routine expression systems such as E.coli with the -bungarotoxin as an example. First, on the basis of the reported amino acid sequence of alpha-bungarotoxin, DNA sequence of -bungarotoxin was deduced and four partially complementary oligonucleotide fragments were designed. The coding region of -bungarotoxin was obtained by renaturing the DNA fragments, nick filling-in, ligation and PCR. The coding region of -bungarotoxin was cloned into plasmids pGEX-2T, named pDZ04, and transformed E.coli BL21 in order to study the expression of alpha-bungarotoxin gene. The results of SDS-PAGE analysis showed that the recombinant plasmid pDZ04 could express efficiently in BL21, and the fusion protein took up about 30%-40% of total bacterial protein. Finally, The biological activity of the recombinant alpha-bungarotoxin and the fusion protein was studied with the natural alpha-bungarotoxin purified from the snake venom as control, ELISA results showed that they had similar antigenicity.